The NE Atlantic rift and break-up system followed the Caledonian structural trends from a regional perspective. Upon closer examination, however, significant differences between the structural orientation and organization of the mapped linear NE–SW Caledonian trends and the oblique and segmented NE Atlantic rift and break-up system are evident. There are significant variations between the northern and southern regions of the Bessel Fjord (at latitude c. 76° N), which appears to be a pivotal point in the evolution of the NE Greenland margin. These variations include the remnants of the continental collision (S-type granites and metamorphic rocks), post-orogenic collapse A-type granites and Old Red Sandstone successions, structural basin configuration, gravity and magnetic anomalies, and break-up-related magmatism. This study provides a first attempt to combine offshore geophysical data along with onshore geological and petrological data from the NE Greenland margin to assess the impact of the different Caledonian stages on the evolution of the subsequent rift basin and margin. A compilation of geochronological data indicates that both Caledonian continental collision (425–400 Ma) and post-orogenic collapse (400–375 Ma) do not show significant along-strike temporal variations across NE Greenland. In fact, structural and petrological data show that Late Devonian–Early Carboniferous transpression (360–340 Ma) involved ultrahigh-pressure metamorphism and the exhumation of deep crustal levels along major north–south-trending shear zones north of Bessel Fjord. To the east, the offshore Danmarkshavn Ridge appears to be elongated parallel to the onshore shear zones. Though the individual ridge segments step eastwards in a northerly direction, the ridge-bounding faults show a consistent north–south orientation, suggesting a deeper structural control.

A new tectonic model is presented to explain the tectono-stratigraphic evolution of the Paleoproterozoic Karrat Group in central West Greenland and the polyphase deformation, magmatism, and metamorphism of the Rinkian orogen. Sedimentation of the Karrat Group initiated after ca. 2000 Ma in an intracratonic rift basin with basal quartzites overlying Archean gneisses of the Rae craton. Rift-related alkaline volcanic rocks and synrift siliciclastic sediments were deposited in the north while an evaporite-carbonate platform developed in the south. The rift basin evolved to a back-arc basin, with associated subalkaline volcanic rocks, concomitant with the intrusion of arc-related granitoids of the Prøven igneous complex along the basal contact of the Karrat Group between 1900 Ma and 1850 Ma. The Karrat Group and magmatic arc rocks underwent metamorphism ca. 1830−1800 Ma during the collisional phase of the Rinkian orogeny. The metamorphic grade of the Karrat Group increases from greenschist facies in the south to granulite facies in the north, where it is marked by migmatization and emplacement of S-type leucogranites. Extensive east-southeastward thrust emplacement and fold vergence characterize the Rinkian orogen south of the Prøven igneous complex magmatic arc, where the arc-continent collision is established along a top-to-the-ESE shear zone postdating the Rinkian metamorphism. In summary, the Karrat Basin developed on the upper plate above eastward-dipping subduction and, together with the Rinkian orogen, represents the result of arc-continent collision that initiated the structuring of a back-arc fold-and-thrust system antithetic to the subduction system.

Mafic volcanic rocks of the Kangilleq Formation of the Paleoproterozoic Karrat Group host volcanogenic massive sulfide (VMS) mineralization in the area of central Kangiusap Kuua, central West Greenland. The mafic volcanic rocks display evidence of subaqueous, effusive eruption and redeposition by mass debris flows generated along fault scarps on the sea floor. A zone of semiconformable quartz alteration and disconformable chlorite alteration within hydrothermal breccias and mafic tuff breccias near the top of the volcanic sequence is interpreted to reflect a synvolcanic hydrothermal system. Conformable, massive to semimassive, and discordant, stringer-style sulfide mineralization is hosted within the quartz- and chlorite-altered volcanic rocks. The massive to semimassive sulfide mineralization is similar to 10 m thick and crops out along strike for similar to 2,000 m. The stringer zone is <= 10 m thick with individual sulfide stringers ranging in width from 5 to 90 cm. All sulfide zones are dominated by coarse pyrrhotite and pyrite, with trace amounts of sphalerite and chalcopyrite. The pillow lavas are subalkaline with geochemical characteristics typical of modern transitional to tholeiitic mid-ocean ridge or back-arc basin basalt. Trace element and Nd isotope data suggest that these lavas erupted in an epicratonic, back-arc basin. Characteristics of the host rocks indicate a period of localized rifting, volcanism, and VMS formation during genesis of the Karrat Group, which is dominated by siliciclastic rocks.

The Late Eocene-Oligocene post-breakup magmatism of the North Atlantic Igneous Province (NAIP) in East Greenland, is represented by sub-volcanic intrusions associated with a NE-SW oriented magmatic lineament, the Werner Bjerge Rift. This onshore magmatism extends for more than 100 km from eastern Traill & Oslash; to Werner Bjerge. In the same region, strike-slip post-breakup faulting is documented along N-S trending faults extending more than 300 km from Traill & Oslash; up to the north, along the Loch Fyne Fault Zone. Offshore East Greenland, the NW-SE trending East Jan Mayen Fracture Zone, has represented the northern boundary of the Jan Mayen Micro Continent in the Eocene-Oligocene, and extended westward, toward Traill & Oslash;. The Werner Bjerge Rift, the Loch Fyne Fault Zone and the East Jan Mayen Fracture Zone were active during the Late Eocene-Oligocene and intersected in eastern Traill & Oslash; with a 120 degrees angle, resembling a triple junction. This study presents the onshore deformation and magmatism associated with a failed triple junction that was active between 40 and 25 Ma, highlighting the importance of inherited structures in response to stress variations and plate tectonics modifications. The tectonic trends of the Fault-Fault-Ridge Traill & Oslash; triple junction are inherited structures from the Caledonian Orogeny and from multi-stage rifting episodes that characterized the East Greenland basin system since the Late Carboniferous. New age and geochemistry of the magmatism in the Werner Bjerge Rift, combined with structural analyses of fault systems suggest that the Traill & Oslash; triple junction was generated by plate tectonics configuration and not by a mantle plume. Triple junctions, the place where three tectonic plates meet, are often associated with mantle plumes. However, the hypothesis of divergent triple junctions linked to the initial doming of continental lithosphere above a mantle plume-head has been questioned by recent geological, geophysical, and numerical modeling studies. In this paper we describe structures and magmatism associated with a failed triple junction in Traill & Oslash; (East Greenland), that was active in the Late Eocene-Oligocene, between 40 and 25 Ma ago. The triple junction formed in the aftermath of mantle plume action within the North Atlantic Igneous Province and appears primarily controlled by lithosphere structure and inherited structural trends. The data indicate that pre-existing thermal and mechanical heterogeneities in the lithosphere could significantly impact the propagation, orientation, localization, and distribution of continental rifts and triple junctions. The N-S trending Loch Fyne Fault Zone, characterized by left-lateral strike slip faults, represents the failed arm of a triple junction The Werner Bjerg Rift is a Late Eocene-Oligocene failed rift characterized by alkaline magmatism similar to the East African rift Inherited structural trends, stress variations, and plate tectonics modifications primarily control the failed triple junction in Traill & Oslash;

Accurate palaeogeographical reconstructions of past supercontinents are necessary to test models of supercontinent cyclicity, secular variation in plate tectonics and mantle geodynamics. However, numerous factors limit our ability to reconstruct past supercontinents as is evident in the ongoing debates regarding the construction phase and geometry of Earth's most recent supercontinent, late Paleozoic to early Mesozoic Pangaea. An important factor in these debates, and a focus of our study is how best to palinspastically restore, in section and in plan-view, the orogenic belts along which supercontinents were stitched together. We utilize the orogenic belts spanning Baffin Island, Greenland and Fennoscandia that are inferred to record the assembly of the Paleoproterozoic supercontinent Columbia to test the accepted reconstruction of the Nuna core of Columbia. We show that as reconstructed in the Nuna model, each of Baffin Island, Greenland (with some complications) and Fennoscandia are characterized by an older cratonic backstop that gives way to younger accretionary complexes toward the inferred oceanic domain that lay to the south and which is inferred to have closed by subduction beneath northeastern Laurentia-Fennoscandia during Columbia assembly. This southward transition from cratonic backstop to accretionary orogen is a hallmark of upper plates in modern convergent plate margins and is consistent with the construction of the Columbia supercontinent, including its Nuna core, through plate tectonic processes, and provides a broad validation of the Nuna reconstruction and hence for Columbia as a whole. Map view curvature of the cratonic backstops is restricted to long wavelength, open bends consistent with the Archean crust having been characterized by significant lithospheric strength. The more accretionary southern portions of Nuna are, however, characterized by sinuous orogens that developed by oroclinal bending of formerly more linear belts, significantly complicating their palinspastic restoration and rendering detailed correlation of juvenile orogenic belts across Nuna problematic.

ABSTRACT Siliciclastic and volcaniclastic sediments in a volcanic rifted-margin succession may experience a complex diagenetic history during burial that can have a large impact on sandstone reservoir properties. To understand such changes, variations in initial sediment composition and succeeding diagenetic changes have been studied for a Paleogene outcrop analogue in the Kangerlussuaq area, East Greenland. The nature of the mafic volcanics-bearing succession, which consists of intra-volcanic sandstones, accommodated over quartz-rich pre-volcanic fluvial sandstones, are comparable to the settings of recently discovered hydrocarbon-producing sandstones in the Faroe–Shetland Basin on the conjugate Atlantic margin. Our petrographic and provenance investigations of the pre- and intra-volcanic sandstones are supported by geochemical and X-ray diffraction analyses. The intra-volcanic sandstones were deposited in shallow marine environments with mixed siliciclastic and volcaniclastic input, the latter rich in felsic to mafic volcanic rock fragments and feldspar grains. Similar zircon age distributions of pre- and intra-volcanic sandstones support a continued supply from the same siliciclastic sediment source after the onset of volcanism. Variations in initial detrital grain and pore-fluid (fresh to marine) compositions resulted in different diagenetic changes in the pre- and intra-volcanic sandstones. However, where siliciclastic sandstones were overlain by volcaniclastic rocks rather than massive lava flows, the diagenetic changes resemble those of the intra-volcanic sandstones. The cementing phases are typically quartz, illite (probably illitized kaolinite), and rare anatase in the pre-volcanic sandstones. Chlorite, calcite, zeolite/feldspar, opal/quartz, and titanite are characteristic authigenic phases in the intra-volcanic sandstones. Precipitation of different minerals in the pre- and intra-volcanic sandstones show that the detrital composition (and to a lesser extent depositional environment) played a major role during early and late diagenesis after deep burial (up to 6–8 km). Inter-eruptive siliciclastic units may prove to form highly valuable reservoirs when they are composed of mixed siliciclastic and volcaniclastic material. In the stratigraphically youngest intra-volcanic sandstones and pre-volcanic sandstones overlain by hyaloclastite or tuff, there is a high potential for preservation of interparticle porosity during burial (< 5 km) due to early chlorite rims and the generation of secondary porosity after the dissolution of early zeolite cement.

The Paleoproterozoic Mârmorilik Formation in the Karrat basin of West Greenland hosts the Black Angel Zn–Pb deposit. Chlorine-rich scapolite, zones with vuggy porosity and quartz nodules in the ore-bearing marble are herein interpreted to represent metamorphosed, vanished, and replaced evaporites, respectively. Mineralization is closely associated with anhydrite with δ 34 S values (5.2–12.6‰) broadly comparable to published values for Paleoproterozoic seawater sulfate. Considering the fundamental attributes of the mineralization and host sequence, a Mississippi Valley-type (MVT) model is the most obvious explanation for mineralization. Overlying the ore-bearing sequence are organic-rich semipelites and massive calcitic marbles, which may have served as seals for hydrocarbon or reduced sulfur and acted as chemical traps for deposition of the sulfidic ore. The Mârmorilik Formation contained an interlayered sulfate-rich evaporite-carbonate sequence, a common setting for MVT deposits in the late Neoproterozoic and Phanerozoic, but unique among the few known MVT deposits in the Paleoproterozoic. This ca. 1915 Ma evaporite-carbonate platform is younger than sulfate evaporites deposited during and immediately after the ca. 2220–2060 Ma Lomagundi carbon isotope excursion and records a significant seawater sulfate level during a time interval when it was assumed that it had been too low to form extensive evaporite deposits. Therefore, MVT and clastic-dominated (CD) Zn–Pb deposits in the geological record might progressively fill the apparent gap in marine sulfate evaporites and provide unique insights into Proterozoic seawater sulfate level. Considering the sequence of tectonic events that affected the Karrat basin, the mineralization took place between Nagssugtoqidian collision (< 1860 Ma) and Rinkian metamorphism (ca. 1830 Ma).

A new tectonic model is presented to explain the tectonostratigraphic evolution of the Paleoproterozoic Karrat Group in central West Greenland and the polyphase deformation, magmatism and metamorphism in the Rinkian orogen recorded in Paleoproterozoic rocks and Archaean complexes. The Karrat Group (from c. 71°00’ to 73°00’ N) formed in an intra-cratonic sag basin after c. 2000 Ma with basal quartzites of the Qaarsukassak and Mârmorilik formations unconformably overlaying Archaean gneisses of the Rae Craton. From 1950 to 1900 Ma a carbonate platform represented by the Mârmorilik Formation developed toward the south, while rift related alkaline volcanic rocks represented by the alkaline member of the Kangilleq Formation and syn-rift siliciclastic and volcaniclastic sediments of the Nûkavsak Formation were deposited to the north. The rifting was succeeded by a back-arc system, represented by the transitional member of the Kangilleq Formation. Concomitantly with development of the back-arc system, arc-related granitoids of the Prøven Intrusive Complex (PIC) intruded into and along the basal contact of the Karrat Group around 1900 Ma with major pulses at c. 1870 and c. 1850 Ma. The Karrat Group and the magmatic arc rocks underwent HT-metamorphism at c. 1830–1800 Ma during the collisional phase of the Rinkian orogen. The metamorphic grade increases from greenschist facies in the south, to granulite facies in the north, where the metamorphism is associated with migmatization and emplacement of the S-type Qinngua leucogranites. Extensive thrust emplacement and folding characterize the Rinkian orogen south of the PIC and the eastern boundary of the magmatic arc is reworked along a top to ESE shear zone post-dating the HT-metamorphism. The ESE-ward emplacement of allochthonous thrust sheets during an early stage of thin-skinned tectonics is followed by NE-ward emplacement of basement nappes and finally by a NW-SE compression stage resulting in tectonic inversion of basin normal faults. The back-arc extension and Cordilleran-type magmatism were driven by eastward subduction of oceanic crust during the Trans-Hudson Orogeny resulting from the convergence of the Superior, Meta Incognita and Rae Archean cratons between 1870–1800 Ma. The Karrat Group north of the PIC together with the time-correlative Piling Group of Baffin Island (Canada) probably represented the passive margin succession of the Rae craton that evolved into a forearc setting during the Trans-Hudson Orogeny. The Rinkian orogen is an example of Cordilleran-type tectonics resulting from the deformation of the Rae continental margin intruded by magmatic arc granites during subduction, followed by HT-metamorphism in the upper plate and the structuring of a back-arc fold and thrust system antithetic to the subducting plate.

The Black Angel Zn-Pb ore deposit is hosted in folded Paleoproterozoic marbles of the Mârmorilik Formation. It is exposed in the southern part of the steep and inaccessible alpine terrain of the Rinkian Orogen, in central West Greenland. Drill-core data integrated with 3D-photogeology and hyperspectral imagery of the rock face allow us to identify stratigraphic units and extract structural information that contains the geological setting of this important deposit. The integrated stratigraphy distinguishes chemical/mineralogical contrast within lithologies dominated by minerals that are difficult to distinguish with the naked eye, with a similar color of dolomitic and scapolite-rich marbles and calcitic, graphite-rich marbles. These results strengthen our understanding of the deformation style in the marbles and allow a subdivision between evaporite-carbonate platform facies and carbonate slope facies. Ore formation appears to have been mainly controlled by stratigraphy, with mineralizing fluids accumulating within permeable carbonate platform facies underneath carbonate slope facies and shales as cap rock. Later, folding and shearing were responsible for the remobilization and improvement of ore grades along the axial planes of shear folds. The contact between dolomitic scapolite-rich and calcitic graphite-rich marbles probably represents a direct stratigraphic marker, recognizable in the drill-cores, to be addressed for further 3D-modeling and exploration in this area.

AbstractMeta-sedimentary rocks recovered beneath Palaeogene basalts near the base of Ocean Drilling Program (ODP) Leg 152-917A offshore South-East Greenland were thought to be of Late Cretaceous age. This interpretation, however, has several inconsistencies as it requires a tectono-metamorphic event during the Cretaceous not recognized in the North Atlantic region, and the presence of a wide Mesozoic sedimentary basin that extended from SE-Greenland to the Rockall Plateau, for which there is currently no evidence. Here, we report a Neoproterozoic U/Pb apatite age of 905 ± 21 Ma and a younger 40Ar/39Ar isochron whole-rock age of 820 ± 40 Ma for an altered tuff layer that occurs in the upper part of the meta-volcaniclastic sequence recovered from hole 917A. The 40Ar/39Ar step-heating ages on biotite and whole-rock mini-cores from deeper in hole 917A yielded Palaeoproterozic dates that cluster around 1950 to 1850 Ma, pointing toward a Palaeoproterozoic source. The U/Pb apatite date is interpreted as the eruption age of the tuff layer, whereas the younger whole-rock 40Ar/39Ar age is consistent with low-temperature greenschist alteration of volcanic glass and secondary mineral growth during sedimentary burial in an extensional regime. The c. 905 Ma age for the tuff provides the first evidence for Neoproterozoic rocks offshore South-East Greenland and suggests a correlation between this sequence and the Torridon Group in the Hebridean Foreland of the Scottish Caledonides. The calc-alkaline nature of the volcaniclastic rocks and the age of the tuff layer point toward a source area with arc-magmatism related to the Renlandian event of the Valhalla Orogeny.

Integration of field structural data and 3D-photogeology from the southern part of the Rinkian Orogen, in central West Greenland, indicates that Paleoproterozoic marbles of the Marmorilik Formation were deformed by two compressional events in the foreland of the orogen, associated with tectonic inversion of normal faults. Tectonic transport and folding post-date the Rinkian metamorphism (c. 1830-1800 Ma) with the first event characterized by NNE-SSW oriented compression and tectonic stacking of folded calcitic marbles (Black Angel Tectonic Unit), above slightly deformed dolomitic marbles (South Lakes Tectonic Unit). The second event caused the inversion of NE-SW trending normal faults during NW-SE oriented compression. Field observations reveal that the normal faults have a listric geometry and were inverted after c. 20 tilting to the NE of the Maarmorilik carbonate platform. The style of tectonic inversion reflects the amount of extension accommodated along the listric faults showing rollover anticlines and extensional fault-bend-folds in the hanging wall, then inverted as thrust anti-clines, back-thrusts antithetic to the normal fault or normal faults passively truncated by younger thrusts. This paper shows the power of 3D-photogeology that can provide observations of lithostratigraphic units and structural data to allow investigation of remote areas from otherwise inaccessible outcrops.

Hyperspectral imaging is an innovative technology for non-invasive mapping, with increasing applications in many sectors. As with any novel technology, robust processing workflows are required to ensure a wide use. We present an open-source hypercloud dataset capturing the complex but spectacularly well exposed geology from the Black Angel Mountain in Maarmorilik, West Greenland, alongside a detailed and interactive tutorial documenting relevant processing workflows. This contribution relies on very recent progress made on the correction, interpretation and integration of hyperspectral data in earth sciences. The possibility to fuse hyperspectral scans with 3D point cloud representations (hyperclouds) has opened up new possibilities for the mapping of complex natural targets. Spectroscopic and machine learning tools allow or the rapid and accurate characterization of geological structures in a 3D environment. Potential users can use this exemplary dataset and the associated tools to train themselves or test new algorithms. As the data and the tools have a wide range of application, we expect this contribution to benefit the scientific community at large.

Evaluation of the regional geotectonic impact of the High Arctic Large Igneous Province (HALIP) in the present‐day northern Atlantic region has been hindered by poor correlation between the Svalbard–Barents Shelf region and eastern North Greenland. New sedimentological and biostratigraphic data from Peary Land and Kronprins Christian Land (Kilen), North Greenland reveal that the Lower Cretaceous palaeogeographic and sequence stratigraphic development of this area is closely comparable to that of Svalbard. The succession records Hauterivian – early Barremian regional uplift and emergence followed by fluvial sedimentation and subsequent transgression in the late Barremian – early Aptian. Recognition of this tectonically forced regression in North Greenland provides a link to a coeval well‐known tectonostratigraphic event in the Svalbard region, and hence to regional tectono‐magmatic uplift heralding the HALIP and the initiation of the Amerasia Basin.

In East Greenland, sedimentation during the Middle Devonian‐earliest Carboniferous interval was characterized by the Old Red Sandstone Molasse Basin deposits. The continental succession recorded folding and intrabasinal unconformities associated with the activation of extensional detachments and core complex formation which post‐dated high‐ P granulite facies metamorphism at c . 403 Ma. The extensional collapse responsible for the initiation of the Devonian basin and associated bimodal magmatism must be understood in the context of continued continental convergence during the Early Carboniferous, required by ultrahigh‐pressure metamorphism in North‐East Greenland at c . 355 Ma. Along a small nunatak within the Wordie Gletscher in Payer Land, NE Greenland (lat. 74°N), Precambrian gneisses recording Devonian granulite‐facies metamorphism are in tectonic contact with the molasse deposits along an ESE‐ward dipping thrust fault: the Scotstounhill Thrust. This paper will discuss the role of Devonian contractional structures and contemporaneous extensional faulting and present a new tectonic model that accounts for the exhumation of deep crustal rocks by these coupled mechanisms.

Permian to Triassic outcrops in East Greenland diminish significantly northwards. Understanding the northward extent, and nature, of the Permian and Triassic successions has implications for regional palaeogeographic reconstructions and exploration in adjacent offshore basins. Examining the structural relationships between the basement, Permian, Triassic, Jurassic and Cretaceous successions can further our understanding of the tectonic evolution of the region. Here, we describe a hitherto overlooked section through the Permian to Cretaceous from central Wollaston Forland and consider its structural context. The western side of Permpasset forms the upthrown eroded crest of a horst block, which provides exposure of the earliest stratigraphic intervals in the region. The fractured Caledonian basement is overlain by evaporitic marine limestone facies of the Karstryggen Formation, which are succeeded by shallow marine sandstones assigned to the Schuchert Dal Formation, both Upper Permian. The overlying unit records a period of fluvial deposition and is not possible to date. However, an Early to Middle Triassic age (Pingo Dal Group) seems most likely, given regional eustatic considerations. This is, therefore, the most northerly record of Triassic strata in North–East Greenland. West of the horst structure, fine-grained sandstones and bioturbated siltstones of the Jurassic (Oxfordian) Jakobsstigen Formation are recorded. These were downfaulted prior to a prolonged hiatus after which both the Triassic and Jurassic strata were draped by Cretaceous shales of the Fosdalen Formation. The Cretaceous succession is overlain by a thick basalt pile of Eocene age, heralding the opening of the North-East Atlantic. Glendonites overlie Oxfordian siltstones at the base of the middle Albian Fosdalen Formation. These were likely winnowed from slightly older Cretaceous strata and overlie the hiatus surface between the Jurassic and Cretaceous. This is the first record of glendonites from the Cretaceous of East Greenland and they are interpreted to record the Circum–Arctic late Aptian – early Albian cooling event.

ABSTRACT The Rosebank hydrocarbon discovery in 2004 proved that intra-lava sandstones form attractive reservoirs in the Faroe–Shetland Basin and the new volcanic play triggered the need for suitable analogues to describe and assess sedimentology, reservoir architecture, compartmentalization, and connectivity of intra-lava siliciclastic units. The onshore Kangerlussuaq Basin in East Greenland offers the opportunity to study Paleogene intra-lava siliciclastic sandstones and their interaction with lavas, on the scale of the Rosebank Field. The focus of this study is a siliciclastic-dominated intra-lava unit, 4–10 m thick, exposed in almost vertical cliff sections over distances of several kilometers. The unit reflects a short return to siliciclastic deposition following initiation of volcanic activity and extrusion of the first lava flows in the area. Deposition took place as shoreface and delta progradation in a marine-influenced, shallow embayment. Lateral variations in sedimentary facies distribution and geometry are prominent and were largely governed by an interplay of base-level variations and autocyclic processes, the surface roughness and type of substratum on which deposition took place, and differential block movements before and during deposition. Presence of local topographic barriers are of key importance and influenced the lava–sediment interaction and the resulting 3D-geometry of lava flows and sediment bodies. In addition, compartmentalization of the intra-lava sandstone unit is observed and is controlled by the offset across normal faults, intersecting dikes, and to a lesser extent by invasive and eroding lavas. A depositional model is suggested that incorporates the detailed sedimentological and 3D photogrammetric observations and presents a possible explanation for the contrasting architecture of the intra-lava unit observed in three areas located a few kilometers apart. The model embraces the complex interplay between siliciclastic and volcanic settings and reveals important aspects to consider when recoverable volumes of hydrocarbons are estimated in intra-volcanic subsurface reservoirs in volcanic rifted margins with poor seismic imaging of the relatively thin intra-lava reservoirs.

Basement highs are large structural features, commonly buried in sedimentary basins (Busby & Azor 2012). They are of interest for natural resources exploration and research because of their ability to influence migration and entrapment of petroleum (Trice 2014) and water, and the deposition of metals (Hitzman 2005; Borg et al. 2012). Three-dimensional (3D) reservoir models (e.g. Shepherd 2009) are built to evaluate and model fluid-filled basement reservoirs (Ringrose & Bentley 2015). However, subsurface data are expensive, difficult to obtain and are often widely spaced. Ideally, basement reservoir models would be constrained by rock, fracture and mineral vein data from appropriate outcrop analogues (acknowledging that subaerial basement rocks have, by definition, a different uplift history than subsurface basement). The Liverpool Land Basement High (LLBH) in Greenland is an uplifted and well-exposed basement high located between two sedimentary basins, and thus provides a valuable analogue for fractured basement-hosted mineral, oil and geothermal reservoirs. The Geological Survey of Denmark and Greenland (GEUS) conducted reconnaissance work on the LLBH in 2018 to assess the quality of the exposure of basement palaeo-weathering profiles and fault-fracture networks. Here, we introduce the LLBH, the concept of fractured basement reservoir modelling, and how studying the LLBH can help enhance reservoir modelling of fractured basement. We present some of our preliminary observations of LLBH fault-fracture networks and discuss how the exposed sediment-basement features and processes might aid industry and research in their top basement mapping activities. We propose that LLBH provides a particularly suitable analogue for industry and research to analyse: (a) multiscale fracture system connectivity, (b) fluid migration and fluid-rock reaction processes, (c) input parameters for basement reservoir modelling and (d) top basement geomorphologies and processes.

The geology of the Paleoproterozoic Karrat Group in West Greenland (71°–74°50´N) was investigated during the field seasons 2015–2017, using a combination of digital photogrammetry and traditional field work in a collaboration between the Geological Survey of Denmark and Greenland and the Ministry of Minerals Resources of Greenland. The area is characterised by steep alpine terrain with more than 2000 m of relief that in many places is completely inaccessible, which makes field work extremely difficult. Therefore 3D mapping using digital photogrammetry is an invaluable tool in the investigation of the region. Early geological investigations of the area involved the first use of photogrammetry in Greenland (Henderson & Pulvertaft 1987). This contribution serves as an example of the present-day use of photogrammetry in geological interpretation, following the workflow outlined in Sørensen & Dueholm (2018). During the last three years, more than 50 000 stereo images have been collected using handheld, calibrated digital cameras while conducting field work in the area (Rosa et al. 2016, 2017, 2018). The images, which cover large parts of the steep cliff sections in which the geology is superbly exposed, are essential to the ongoing revision of the geological map sheets covering the area. Here we present a small subset of the data from the island of Karrat (Fig. 1), showcasing the potential of 3D geological mapping in Greenland as well as presenting new insights into the geology of the Karrat Group.

Summary Good analogues are keys for better understanding petroleum systems in frontier basins and new plays in proven basins. Recent discoveries have proven Permian carbonate plays (e.g. 7120/1–3 and 7220/11-1) in the Norwegian Barents Sea and Triassic siliciclastic plays (e.g. Goliat, Tornerose and Alke Sør) in the North Atlantic. Permian and Triassic plays have been unsuccessfully tested on the Mid-Norwegian continental shelf (M-NCS), but these plays have recently attracted renewed attention. However, the lack of offshore core data from this interval provides a major obstacle in developing valid play models. On the conjugate East and Northeast Greenland margin, excellent outcrops and a large number of shallow fully cored boreholes document the syn- to post-rift Permian–Triassic interval. Data from this interval in East and Northeast Greenland thus provide important constrains on key elements for new play models on the M-NCS. The presentation will provide observations from East and Northeast Greenland that may help to assist the definition of play models for the Permian–Triassic succession in the M-NCS and place them in a tectono-stratigraphic context.